Apparatus to determine the optimum setting of a boat sail

ABSTRACT

An apparatus to measure and display the pressures developed on the surfaces of a boat sail. This apparatus uses an electronic module that attaches to the sail to measure and calculate the surface pressures or differential pressure and transmit this data via wireless link to a separate display unit. The display unit provides a visual display of the measured pressures and a peak indication of the maximum or minimum pressures measured.

CROSS REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED R&D

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REFERENCE TO SEQUENCE LISTING

Not Applicable

BACKGROUND OF THE INVENTION

The differential pressure developed on a boat sail for a given wind condition is a measure of its efficiency. This invention is for an apparatus to measure and display the pressure or differential pressure on a sail and allow the operator to recognize and set the sail conditions that produce maximum efficiency and boat speed. Previous technology required that separate pressure ports be attached to both sides of the sail, and then cumbersome hollow connecting members (tubes) capable of transmitting air pressure were run from these pressure pickups on the sail to a remote indicating device that calculated the pressure or differential pressure and displayed the information. This invention introduces new technology that eliminates the drawbacks of the previous inventions, and provides an information display that is more useful to the operator.

SUMMARY OF THE INVENTION

This invention presents an apparatus that measures the pressures developed on a boat sail, and displays this information to the boat crew in a way that allows them to know when they have achieved maximum sail efficiency. It gives the crew an analytical means of evaluating changes in boat performance resulting from changes that are made to various sailing parameters. The apparatus consists of a small transducer module that attaches to the sail. This transducer module senses the pressure on the sail surface or surfaces, and calculates the actual pressure or differential pressure. It then transmits the data by wireless link to a separate unit for display.

The display unit presents a visual display of the pressure information. It also includes a peak indicator for quickly evaluating trends and the effects of changes in sail parameters. This new technology offers the following changes and advantages over the prior art.

1. The use of small transducer modules affixed to one or to both sides of the sails minimizes disturbances in sail performance and simplifies installation.

2. The transmitter modules can be left in place when raising or lowering the sails. No special care or handling is required as was with the previous systems.

3. Previous technology required that individual tubes be run from the pressure pickup ports on the sail to a remote device that determined and displayed the pressures. Tubes were required so that matter (air molecules) could be conveyed from the pressure port to the remote indicator. Running tubes on a boat was difficult and cumbersome, had a high failure rate, and imposed restrictions on sail utilization. This new invention uses an RF signal. Only energy is transferred between the transducer module that measures and calculates the pressure and the display unit. This system imposes no restrictions on the boat sail utilization.

4. The new technology allows electronic averaging of the pressure readings over time to illuminate the effects of pressure spikes, wind gusts, and turbulence.

5. The new technology incorporates a peak detector which allows the operator to view the peak pressures or differential pressure that were achieved. This makes recognizing trends or the effects of changes in sail parameters easy to comprehend.

DESCRIPTION OF THE DRAWINGS

There are 3 drawings included with this application.

FIG. 1 System Components. Shows the location and installation of the components that make up the system.

FIG. 2 Transducer Module. Shows the makeup and configuration of the Transducer Module.

FIG. 3 Display Unit. Shows the makeup and configuration of the display unit.

DETAILED DESCRIPTION OF THE INVENTION

A sail boat is propelled by the wind. The greater the differential pressure that can be developed on the sail, the greater the driving force, and thus the greater the speed of the boat for a given set of conditions. A number of conditions can affect the pressure differential that is developed across the sail, such as the angle of the sail to the wind, the amount of heel of the boat, the closeness of the jib, etc. Determining the actual conditions that produce the maximum pressure differential is primarily left to the ability of the boat's crew. Devices have been previously proposed to measure the pressure on both sides of the sail, and provide an analytical means of determining the settings that are the most efficient. The previous devices that were developed to provide this information have proved to be ineffective due to serious design limitations. This invention uses new technology to produce a practical apparatus that measures the pressures and provides the information to the boat crew in a way that is easily comprehendible.

The apparatus consists of one or more electrically powered transducers modules that are mounted directly to the sail surface. Each transducer module incorporates a port to access the pressure on the sail surface, and one or more electronic devices to measure the air pressure and produce a digital electrical signal proportional to the measured pressure. This electrical signal may be proportional to the differential pressure measured across the sail, or it may be proportional to the absolute or gauge pressure measured on the sail surface. The transducer module also incorporates the electronics necessary to process and control the electrical signals, and an RF transmitter capable of transmitting the pressure data to the display unit.

These transducer modules can either be mounted to each side of the sail surface, or can be a dual unit that mounts on only one side of the sail and has a pressure port that penetrates through the sail to measure the pressure on the other side. This latter arrangement allows one module to directly measure the pressure on both sides of the sail.

The display unit is an apparatus capable of receiving the RF signal from the transducer modules, processing the information, and displaying the information to the boat crew in a manner that is useful and easily understood. The display unit incorporates one or more display devices that visually present the pressure information. It also has the ability to display the peak differential pressure, or the peak maximum and minimum pressure.

The preferred embodiment consists of a transducer module (1) that is attached to only one side of the sail surface. This is accomplished by first bonding a small adhesive backed Velcro sheet (3) with a hole in the middle to the sail surface.

A small diameter hole is then placed through the sail material. A transducer module with a short tube attached, then attaches to this Velcro sheet. The short tube (4) extends through the sail, giving the transducer module access to the pressure on the back side of the sail. The transducer module (5) incorporates an electronic differential pressure sensor. One side of the sensor is attached to the tube (9) that extends through the sail, the other side of the sensor is attached to a port (7) that measures pressure on the front face of the sail. This combination allows a single sensor to directly measure the differential pressure across the sail. The transducer module is battery powered (6), and incorporates an on/off switch (8), a microprocessor and an RF transmitter to process and transmit the differential pressure data to the display unit. Use of a microprocessor allows the system to average the pressure readings, eliminating the effects of wind gusts, turbulence etc.

The display unit (2) is a separate module designed to receive the data transmitted from the transducer modules, decode it, and display it. The display unit incorporates an RF receiver, a microprocessor, and a series of LED lights (10) that display the relative differential pressure. The transducer module repeatedly measures the pressures on both sides of the sail, calculates the differential pressure, and transmits the data to the display unit The display unit receives the data transmitted from the transducer module, decodes and processes the data and displays the information on its LED displays. Various LED's illuminate or turn off in a rising or falling sequence as the differential pressure increases or decreases. The unit incorporates a peak detector and can display the maximum differential pressure recorded. This combination provides a visual display of the present differential pressure across the sail, relative to the peak differential pressure that has been achieved. It allows the boat crew to instantly evaluate the effects of changes they make in the sail settings. The display unit incorporates a reset switch (11) so the operator can reset the peak display, and indicator lights (14) that displays the battery condition in the modules. Other devices such as an analog meter with a manually settable pointer, a digital display etc. could also be used to display the information 

1. An apparatus for measuring and displaying the differential pressure across a boat sail, said apparatus comprising one or more pressure measuring module temporally attached to one or both sail surface, and a display unit, said pressure measuring module having the ability to measure the pressure on both of the sail surfaces, calculate the differential pressure between the sail surfaces, and transmit the differential pressure data to the display unit via a wireless means, said display unit having means to receive the wireless data, means to process the data, and means to display the value or relative value of the measured differential pressure and the peak value or relative peak value of the measured differential pressure.
 2. An apparatus for measuring and displaying the pressure on both sides of a boat sail, said apparatus comprising one or more pressure measuring modules temporally attached to one or both sail surfaces and a display unit, said pressure measuring module having the ability to measure the pressure on one or both of the sail surfaces, process the data, and transmit the pressure data to the display unit via a wireless means, said display unit having means to receive the wireless data, means to process the data, and means to display the value or relative value of the measured pressures and the maximum or minimum peak value or relative value of the measured pressures. 